Which part of the nephron would be permeable to urea? is it last part of the DCT and collecting duct? And is it regulated by the ADH hormone? Is this the only part where urea is reabsorbed and carried into meddula?Oh I am so confused here, permeable, not permeable, poorly permeablePlease Help!

The Bowman's capsule is obviously permeable to let urea out of the blood and into the nephron, and then a significant proportion is reabsorbed in the PCT which is also permeable. The thin sections of both the ascending and descending regions of the loop of henle are also permeable, but since there is a high concentration of solutes in the renal medulla there isn't much of a concentration gradient for them to use. There are all only slightly permeable - not as much as they are for water for example.

The thick section of the ascending loop of henle, DCT and collecting ducts aren't permeable at all to urea as it's the part you want to concentrate and get rid of!